Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F5/00—Orthopaedic methods or devices for non-surgical treatment of bones or joints; Nursing devices; Anti-rape devices
  • A61F5/01—Orthopaedic devices, e.g. splints, casts or braces
  • A61F5/04—Devices for stretching or reducing fractured limbs; Devices for distractions; Splints
  • A61F5/05—Devices for stretching or reducing fractured limbs; Devices for distractions; Splints for immobilising
  • A61F5/055—Cervical collars
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F5/00—Orthopaedic methods or devices for non-surgical treatment of bones or joints; Nursing devices; Anti-rape devices
  • A61F5/01—Orthopaedic devices, e.g. splints, casts or braces
  • A61F5/04—Devices for stretching or reducing fractured limbs; Devices for distractions; Splints

Definitions

• the object of the invention comprises a method and apparatus for the application of traction or compression force to the patient in the treatment of an injured or diseased part of the musculoskeletal system.
• the invention especially relates to a method and apparatus by which a predetermined traction force can be applied to the patient's cervical spine and maintained unchanged even if the patient's position deviates from the horizontal position.
• a halo vest device In certain kinds of cervical spine injuries it is possible to apply traction force to the patient's cervical spine by putting a halo vest device on the patient.
• the halo vest device has a frame resting on the patient's body, which frame is attached by four support rods to a halo ring secured to the patient's head by pins.
• Figures 5A to 5C represent such a halo vest device. With the help of the threads and locking systems of the rods the desired amount of force can be applied between the supporting structure and the halo ring.
• the halo vest device described above cannot be applied due to the risk of pressure sores.
• One treatment method for such patients is to apply classical head traction. In head traction an arc is secured to the patient's head by pins while the patient is lying in the horizontal position, and a traction force is applied to a wire attached to this arc by attaching weights to the descending end of the wire passing over the sheave. The force applied to the patient's cervical spine is regulated by adjusting the amount of weights.
• the apparatus used is not accurately adjustable and takes up a lot of space with its auxiliary frame. Above all it is inconvenient for the patient and for the nursing staff.
• the use of the apparatus requires that the patient stays in bed lying on his/her back in a horizontal position for several weeks, even for months. This impairs the patient's physical and mental health.
• the blood circulation, metabolism and functioning of the intestines suffer especially from the prolonged lying in a horizontal position.
• the horizontal position also makes nursing the patient, e.g. feeding, washing and physiotherapy very strenuous and time consuming.
• the aim of the present invention is to eliminate the above problems and shortcomings and to present a new method and apparatus for the application of traction or compression force to the patient in the treatment of an injured or diseased part of the musculoskeletal system.
• the invention relates especially to a method and apparatus by which a predetermined traction force can be applied to the patient's cervical spine and maintained unchanged even if the patient's position deviates from the horizontal position.
• the object of the invention thus comprises a method for the application of traction or compression force to the patient in the treatment of an injured or diseased part of the musculoskeletal system, in which a point (b) is situated on the first side of the part to be treated and a point (a) on the opposite side of the part to be treated, (a) being mobile with respect to the point (b), and in which method an essentially constant amount of traction or compression force F 0 is applied to the part L between the points (a) and (b) .
• the point (a) is connected by at least one connecting element R to the point (p) and that such force F R is applied to the connecting element R that it maintains the above-mentioned constant amount of force F Q and compensates any changes in the force acting on the part treated arising from changed angles between the part treated and the horizontal plane and the changes in the direction of the connecting element R, and thus F 0 can be maintained constant even though the patient moves, forming an angle in one or several planes with respect to the horizontal plane.
• the invention also comprises an apparatus for the application of traction or compression force to the patient in the treatment of an injured or diseased part of the musculoskeletal system, in which the point (b) is situated on the first side of the part to be treated and the point (a) on the opposite side of the part to be treated, (a) being mobile with respect to the point (b), and by which apparatus an essentially constant amount of traction or compression force F 0 is applied to the part L between the points (a) and (b).
• the apparatus relating to the invention that it comprises at least one connecting element R by which the point (a) is connected to the point (p) and an element by which such force F R is applied to the connecting element R that it maintains the above-mentioned constant amount of force F 0 and compensates any changes in the force acting on the part treated arising from changed angles between the part treated and the horizontal plane and changes in the direction of the connecting element R, and thus F 0 can be maintained constant even though the patient moves, forming an angle in one or several planes to the horizontal plane, and a force applying device, a control and adjustment device, an acceleration sensor, a force sensor, power sources for the force applying device and the control and adjustment device, a force limiter, and possibly a microprocessor in case adjustment is needed in more than one plane with respect to the horizontal plane.
• the desired force F 0 is maintained constant in amount and direction with respect to the mentioned points so that the changes in the force acting on the mentioned points are recorded, and on the basis of this information the force applying devices used for maintaining the desire force are controlled, where the apparatus consists of the forces and supporting forces relating to the structures, these forces being adjustable according to the above- mentioned principles.
• a constant amount of traction force F 0 is applied to the patient's cervical spine, this force remaining unchanged even if the patient's position deviates from the horizonta position.
• a constant amount of traction force F 0 is applied to the patient's cervical spine by applying the invention to a halo vest device.
• the point a is connected via an intermediate element V by at least two connecting elements R and R' from attachment points c and c', respectively, on the intermediate element V to points p and p' , respectively, on the part B, with part B representing the frame resting on the patient's body, and such compression forces F R and F R , are applied to the connecting elements R and R' that jointly maintain the above-mentioned constant amount of traction force F 0 and which compensate for change in the forces acting on the cervical spine caused by changes in the angles between the cervical spine and the horizontal plane and possibly changes in the attachment co ⁇ ordinates of the points (p), (p'), (c) and (C), so that F 0 can be maintained constant even though the patient moves, forming an angle in one or several planes with respect to the horizontal plane.
• the apparatus relating to the invention comprises a force applying device, a control and adjustment device, an acceleration sensor, a force sensor, power sources for the force applying device and the control and adjustment device, and a force limiter.
• the apparatus also comprises a microprocessor and a sensor measuring angle of swing.
• the invention particularly presents a method and apparatus which enable the patient with a cervical spine injury to be freed from lying on his/her back in an unchanged horizontal position by, e.g., adjusting the patient's bed steplessly up to the vertical sitting position with the traction force on the fracture in the cervical spine automatically maintained constant in spite of the change in position.
• the embodiment relating to the invention described below is also applicable to devices of halo vest type so that a frame resting on the body is temporarily put on the patient, and one or two support points can be taken on the frame in order to maintain the force on the cervical spine constant even if the patient is moved from the bed to, e.g., a wheelchair.
• the embodiment relating to the invention even allows sideways inclinations within certain limits when the patient is in a sitting or half-sitting position without significant changes in the traction force acting on the cervical spine.
• the embodiment relating to the invention is particularly significant because it allows more effective rehabilitation measures than the earlier methods, already at an early stage.
• By altering position circulatory and metabolic disorders caused by prolonged lying in a horizontal position can be avoided, the risk of pressure sores lessened, and the work of the nursing staff facilitated.
• the mental health of the patient endures the problems brought by paralysis better, because the weeks-long unbroken period of lying on the back involved in the first stage when using previous methods is avoided.
• Figure 1 shows the theoretical basis of the invention as seen from the side of the plane T
• Figure 2 shows the theoretical basis of the invention, the plane T being represented as a perspective view
• Figure 3 shows the functional diagram of the apparatus relating to the invention
• Figure 4 shows the acceleration sensor connected to the plane T
• Figures 5A - 5C show the conventional halo vest device as such and when put on the patient
• Figure 6 shows the apparatus relating to the invention applied to halo vest device
• Figure 7 shows the solution presented in figure 6 in a three-dimensional situation
• Figure 1 shows in the form of an example the system's parts, static forces and their summing.
• the inclination of plane T with respect to the horizontal plane may vary
• ⁇ is the angle between the projection of the straight line a-p transferred to the perpendicular plane common to the planes T and P going via the point a and the prolongation of the straight line a-b
• r is the angle between the projection of the straight line a-p transferred to the plane T and the prolongation of the straight line a-b
• M is the mass of the part A
• g is the acceleration caused by gravity.
• the system described above is applicable to a situation where only the acceleration caused by gravity acts on the part A, and of this only a one-directional component needs to be taken into account. If the situation is made more complex so that acceleration appears in three dimensions, several forces acting in different directions must correspondingly be applied to the part A in order to compensate the changes in the forces on the connecting element L caused by the accelerations. In such a case acceleration is measured in the direction of the axes of an orthogonal system of co-ordinates attached in the direction of the connecting element L. The directions of the compensatory forces are selected so that they are parallel, if possible.
• Figure 3 shows the functional diagram of the method and apparatus relating to the invention.
• the force applying device 20 which has been presented as a hydraulic unit in Figure 3, produces the required force on the connecting element R.
• the force applying device is controlled by a control electronics unit 30, which receives information about the force F R via a sensor 15 registering force.
• the sensor used is a strain gauge sensor.
• the sensor is located in a place in which it directly measures force F R (in the present example, the sensor is located on the arm of the hydraulic cylinder 16).
• the information needed by the control electronics on the traction force F 0 , mass M, coefficients K ⁇ and K are given manually (31, 32, 33, 34).
• the electronics need information g x sin measured by the acceleration sensor 10 fixed to the plane T. The sensor is placed so that it measures acceleration in the direction of the connecting element L. In such case the acceleration component parallel to the connecting element is proportional to the product of g x sin ⁇ .
• the setting component of the control electronics calculates the setpoint for the controller.
• the controller 35 compares the setpoint with the signal received from the force sensor and calculates their difference signal.
• the controller e.g. a Pi-controller, controls the force applying device so that the difference signal is zero.
• the reference number 36 represents an amplifier.
• the coefficients K ⁇ and K can also be given automatically to the control electronics by a sensor measuring angle of swing located at the attachment point of the hydraulic cylinder 16 and the plane P (not shown in Figure 3).
• Apparatus includes a force limiter 21 preventing excessive forces from being generated in case of malfunction.
• the limiting can be created, e.g., by a pressure limiter in the control hose.
• the power sources of the force applying device 20 and the electronics unit 30 have been marked by reference numbers 29 and 39, respectively.
• analog electronics will suffice as adjustment electronics. Also in case measurements are needed in three dimensions analog electronics may be sufficient, if the directions of measurement of compensatory forces and accelerations can be appropriately arranged in practice. If this is not possible, the calculation of forces becomes so complex that a microprocessor should be used in computing.
• the disadvantage in this is, e.g., that the parts A and B can be moved only within the limits of the length of the cylinder.
• the force can alternatively be generated by, e.g., a stepper motor with a wire wound around sheaves.
• the advantage in this is the wide range of dynamics, and the disadvantage the difficult- to-handle wiring and deciding where to locate the force sensor.
• a force applying device based on pneumatics can be mentioned.
• the advantage i the light weight of the components, while the disadvantage is the limit set by the velocity of sound on the adjustmen speed.
• strain gauge sensor is one preferred alternative.
• a sensor measuring only one component of acceleration is sufficient as an acceleration sensor.
• a sensor measuring acceleration in three mutually perpendicular directions is used.
• a force limiter depending on the force applying device e.g. a shear pin, a pressure limiter or a friction limiter can be used.
• the connecting element L represents any injured part of the body in general to which a certain amount of force is to be applied.
• the connecting element L is specifically designed to depict th patient's cervical spine to which traction force F Q is to b applied.
• the part B symbolizes the patient's body and the part A the patient's head.
• the required traction force F 0 is applied to the injured part L by applying the required traction force F R to the connecting element R, which has been placed so that it forms an angle of more than 90°, preferably in the range of 160° to 180°, with the part L.
• An alternative method for applying the desired traction force F 0 to the part L is to place the connecting element so that it forms an angle of less than 90° with the part L and to apply compression force equal to the traction force in the previous case to the connecting element R.
• the connecting element must naturally be rigid enough in order to transmit the compression force.
• Figure 6 shows the invention when applied to a halo vest device.
• the centre of gravity of the part A representing the patient's head, is a, which has been connected via the intermediate element V by two, in this case symmetrically arranged, connecting elements R and R' from the attachment points c and c', respectively, on the intermediate element V to the points p and to p', respectively, on the part B (representing the frame resting on the patient's body, i.e., the halo vest device).
• Such compression forces F R an F R are applied to the connecting elements R and R', which jointly maintain the amount of traction force F 0 applied t the patient's cervical spine L constant, and which compensate for the changes in the forces on the cervical spine caused by changes in the angles between the cervical spine and the horizontal plane and possibly in the attachment co-ordinates of the points (p), (p'), (c) and (C).
• the reference numbers 16 and 16' refer to the hydraulic or pneumatic cylinders connected to the force applying device 20.
• the reference numbers 21 represent the force limiters and 15 and 15' refer to the force sensors connected to the controller of the control electronics uni 30. There may of course be three or more connecting elements.
• the force applying device 20 and the control electronics unit 30 are microprocessor-operated. The senso measuring angle of swing is marked by number 10.
• the method and apparatus relating to the present invention can also be applied to exerting the desired compression force on the part L of the patient. If, e.g., in a situation relating to Figures 1 to 3, in which the connecting element R forms an angle of more than 90° with the part L, compression force is applied to the connecting element R, compression force is exerted on the part L. Correspondingly, if R has been placed with respect to L so that they form an angle of less than 90° to each other, the compression force can be exerted on L by applying traction force to the connecting element R.
• the method and apparatus relating to the invention are particularly applicable to the treatment of an injured or diseased part of the patient's skeleton, but it can also be applied more generally in medical rehabilitation directed to the musculoskeletal system. 51

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• Health & Medical Sciences (AREA)
• Nursing (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Orthopedics, Nursing, And Contraception (AREA)

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• 1993
  • 1993-01-20 FI FI930212A patent/FI94832C/sv not_active IP Right Cessation
• 1994
  • 1994-01-17 US US08/481,488 patent/US5697894A/en not_active Expired - Fee Related
  • 1994-01-17 EP EP94904198A patent/EP0680294A1/en not_active Withdrawn
  • 1994-01-17 WO PCT/FI1994/000018 patent/WO1994016651A1/en not_active Application Discontinuation

Patent Citations (4)

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